Silicon-containing particles, typically represented by silicone rubber particles, find use in cosmetic raw materials, as additives to organic resins, etc. A known process for producing such silicon-containing particles consists of curing a curable silicone composition in an emulsification state in an aqueous solution of a surface-active agent (see Japanese Unexamined Patent Application Publication (hereinafter referred to as “Kokai”) S64-51467).
However, since the silicon-containing particles obtained by the aforementioned process contain a large amount of surface-active agents required for the process, they lose some properties inherent in the original silicon-containing particles, such as resistance to heat, electrical characteristics, etc. Furthermore, in the above process, control of particle diameter of the obtained particles largely depends on such factors as type and concentration of the surface-active agent, or emulsifying ability of an emulsifying apparatus, and control of particle diameter of the obtained particles is more difficult when small particles are desired.
On the other hand, known in the art is a process for producing a ceramic material that contains Si, O, and C, the process comprises pyrolysis of a composition that comprises a silicon-containing ceramic precursor polymer (see Kokai H10-275617). Another known process comprises; impregnating graphite with one or more kinds of organic silicon compounds selected from cross-linkable silanes and siloxanes; forming a cross-linked product of the above-mentioned organic silicon compound in the graphite; heating and reacting the graphite in a nonoxidative gas at 300 to 1,200° C., and thus obtaining a C/Si/O composite material (see Kokai 2003-171180).
However, the above-mentioned process for producing a ceramic material involves a process for crushing the ceramic material to form super-fine particles, but the fine particles obtained by crushing have an irregular shape, and therefore it is impossible to obtain a super-fine spherical ceramic material of good flowability and filling ability with the aforementioned known process.
It is an object of the present invention to provide a process for producing silicon-containing particles of an extremely small diameter by a simple process and without using surface-active agents or the like; to provide silicon-containing particles with an easily controllable diameter, with excellent dispersibility in an organic polymer, and with high rate of ceramification by baking; and to provide an organic polymer composition that is characterized by excellent flame-resistant properties, heat resistant properties, and mechanical characteristics, such as ultimate elongation, flexibility, formability, resistance to impacts, abrasive resistance, inner stress relaxation, crack resistant properties, etc.
It is another object of the present invention to provide a process for producing a ceramic material with controllable properties and with extremely small particle diameter in a simple process, as well as to provide a ceramic material that possesses the aforementioned characteristics.